I really like this video! Especially the way the second compared the post-production version with the original footage. Although there were a few times when I felt like like some of the effects were too much.

So in the sky replacement shots, the car moves thru the scene–a simple mask won't work. Did you roto the whole thing? Also, your flourish animations, how did you animate it? Looks like more than a simple mask stroked along a path…are there multiple masks and paths or something else?